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US 4,416,703 AGranted
System for removing debris from pipelines
AssigneeShell Oil Company
InventorPaul R. Scott
Life of this patent
Estimating the term…
Abstract
To remove particulate debris from a pipeline, a plug train including at least one gel plug having debris entraining characteristics and at least one pseudoplastic plug is passed through a pipeline and the debris is collected by the gel plug. The gel plug is pushed through the pipeline with a scraper which in turn may be pushed by liquid or gas pressure.
Claims9
A method for removing particulate debris from a pipeline comprising, inserting a debris entraining gel plug into the pipeline with at least one pseudoplastic plug;
- moving the gel plug through the pipeline by a circulating motion essentially generating a closed toroid, the wall of the toroid adjacent the wall of the pipeline remaining relatively stationary and the center moving in the direction of motion of the gel plug;
- collecting at least part of the particulate debris with the gel plug;
- moving the pseudoplastic plug through the pipeline by viscoelastic flow;
- sealing the gel plug from fluid in the pipeline with the pseudoplastic plug;
- isolating the gel plug from the pseudoplastic plug with a mechanical separator;
- and collapsing the separator up to 40% of the diameter of the pipeline while moving the separator over debris in the pipeline and while substantially maintaining the seal between the gel plug and pseudoplastic plug.
3 more elements
Dependencies are inferred from the claim text.